In the beginning, there was nothing but Uranus and Gaia. Uranus was the sky and Gaia was the earth. Every night, Uranus would come to mate with Gaia, but when she tried to give birth, Uranus would shove her children back inside.
Uranus was an asshole.
Gaia was in great pain and crafted a weapon from flint. She went to each of the children within her and asked if they would use the weapon to kill their father. All refused except Kronos. When Uranus came one night, Kronos cut his testicles off and threw them into the water (where, amusingly, they became Aphrodite). It was into this world that Prometheus was born, conjoined with his brother Epimetheus. After they were separated, they found that Epimetheus could see the past, and Prometheus could see the future.
Prometheus is the god of forethought.
Kronos realized there was an eternal cycle of war. Divine children were more powerful than their parents and would eventually overthrow them. Like Uranus, Kronos sought to maintain his rule, and so swallowed his children. Eventually, his son Zeus escaped being swallowed. He poisoned Kronos to make him vomit out the other gods, and a great war began. Prometheus, predicting the gods would win, sided with Zeus and helped bring down Kronos. There was a period of relative peace, during which Prometheus began making things. He invented music, art, literature and, last of all, humans.
Prometheus is the god of creation and the arts.
The Golden Age began. Humans lived as gods and Zeus killed them. Prometheus created humanity again and the Silver Age began. Humans refused to worship the gods and Zeus killed them. Prometheus created humanity again and the Bronze Age began. Humans fought among themselves and Zeus killed them. Prometheus created humanity again and the Iron Age began. That’s us, the iron people. Our blood is red because it’s filled with iron.
Prometheus is the god of all humanity.
I imagine that Prometheus became fed up with watching Zeus slaughter his children. I imagine him holding the broken bodies of his creations and weeping. I also imagine Prometheus realizing there could be no safety for humans while gods had power over them, so he set forth to destroy the gods.
Prometheus is the god of atheists.
Zeus’s power came from two sources: sacrifices and technology. Humans had to burn the best parts of their food as an offering to the gods. Prometheus tricked Zeus into changing that so humans only sacrificed fat and skin and bones. Humans lived in the cold, dying without shelter and warmth. Prometheus stole Zeus’s thunderbolt and gave it to humanity, giving them fire, and the knowledge of how to build homes and tools.
Prometheus is the god of being a sneaky bastard.
Zeus punished Prometheus by chaining him to a rock. Every morning, an eagle came and ripped Prometheus open to eat his liver. In some stories, he is eventually freed by Hercules.
I like to think Prometheus is still there, holding out. You see, the price for Prometheus’s freedom was the betrayal of another. Someday, Zeus would, as his father and grandfather, be destroyed by his child. Zeus didn’t know how to save himself, but Prometheus, god of forethought, did.
There were two possible futures. Zeus would father Ares, the god of war, and be destroyed by him. The other future, kept secret by Prometheus, was that Zeus could kill his wife, Memnosyne, before she gave birth. If Zeus swallowed Memnosyne, Athena, the god of war, would be born from the top of Zeus’s head. Athena, unlike Ares, would be born a woman and unable to destroy her father.
The ancient Greeks were terribly sexist.
I like to think Prometheus sees the daily arrival of the eagle with great relief. He had saved Memnosyne (and, perhaps, all of humanity) for another day. I imagine Prometheus, still chained to a rock, watching humanity with proud eyes, holding out for us all.
Prometheus is the god of self-sacrifice.
There's more to the story, about Pandora and hope, but you can find out about it, yourself. If I've made you look into his story, that makes Prometheus proud, too.